How much electricity does a computer monitor use per hour?

Between 12 and 14 watts while running, so roughly 0.01 kWh an hour at the middle of that range. At 18.44¢ per kWh that is about 0.00 dollars an hour.

How much electricity does a computer monitor use in 24 hours?

Left on for a full 24 hours it uses about 0.31 kWh. That is a different question from a typical day, which for most households is far fewer hours — the two answers differ by several times.

How much electricity does a computer monitor use when off?

On standby it draws 0.15 to 0.3 watts. Small per hour, but it runs every hour of the year, which is why standby is worth counting separately from use.

Devices

How many watts does a monitor use?

A 24-inch monitor draws **13 watts** while you are using it. That is the median of 504 certified models, and the middle half fall between 12 and 14 watts. Eight hours a day for a year costs about **$7**. This is one of the few appliances where the honest answer is that it does not matter.

Work it out with your own tariff

Hours used per day

1h 2h 4h 6h 8h All day

Your rate, cents per kWh

12 18.44 (US avg)30 52

Cost of running this device at 13 watts and 18.44 cents per kilowatt-hour
Period	Cost	Hours counted
One hour running	$0.00	1 hour
A full 24 hours on	$0.06	24 hours
A day of typical use	$0.01	4 hours
A month	$0.29	4 h/day × 30
A year	$3.50	4 h/day × 365

13 W × 4 h ÷ 1000 = 0.05 kWh × 18.44¢ = $0.01 for a day of typical use.

Calculated at 13 W, the middle of the 12–14 W range. Rate defaults to 18.44¢ (U.S. Energy Information Administration, 2026-05) — a national average, which is wrong for you specifically, so put your own in above.

Bigger screens, but not by much

Screen size	Middle half draws	Median	Models measured
23-25 inch	12-14 W	13 W	504
26-27 inch	14-21 W	17 W	518

A monitor is not a small television

A 24-inch monitor draws 13 W. A 34-to-43-inch television draws a median of 63 W — roughly five times more for maybe three times the screen area. The difference is brightness: a television is built to be watched from across a lit room, a monitor to be read from two feet away.

This matters because television figures get reused for monitors in the same articles. They are not interchangeable.

Switching it off saves almost nothing

Sleep draw is 0.15 to 0.30 watts, median 0.21. Fully off, the median is 0.12 W. A monitor left in sleep for an entire year costs about 35 cents.

The advice to switch monitors off to save money is, at current measured figures, worth about a third of a dollar a year. Switching off a monitor to make it last longer is a different argument and may hold; this page is only about the electricity.

What it costs you specifically

Set the hours and your own tariff below.

What this does not account for

Certified displays are a biased sample. Certification is voluntary and efficient models earn it. An uncertified monitor draws more, not less.

Measured under a standard test at default brightness. Real draw scales with brightness, and a monitor at maximum brightness can draw substantially more than the tested default. Gaming monitors with high refresh rates and HDR are also at the high end of, or above, these ranges.

Two large caveats on scope. These are desktop monitors, not laptop screens, which are not certified separately from the laptop. And the largest certified class in this dataset mixes desktop monitors with large-format signage displays, which is why this page stops at 27 inches rather than quoting a figure for 32-inch and above.

Sources

01ENERGY STAR certified displays — measured on-mode and sleep powerU.S. Environmental Protection Agency · Checked 2026-08-21
02Electric Power Monthly, Table 5.3 — average price of electricity to ultimate customersU.S. Energy Information Administration · Checked 2026-08-21

How these figures are produced: see our methodology.

Figures are calculated from published wattages and a published tariff, both dated above. They are good for comparing devices, not for predicting your bill: your rate, settings and usage all differ.